Flight #3
Launch Date: Saturday, June 12, 1999
June 15, 1999
Photogrametric measurements have been completed on the
images recovered from Flight #3.
The current estimate for the max height is 82,800 feet.
June 12, 1999
Success!! Flight #3 lifted off from the Olson farm at 7:56 AM
Central time. Due to high winds aloft, we again used the entire tank
of helium to fill the balloon. Instead of filling and releasing party
balloons to try to estimate the flight path, this time we used a flight
simulation program and wind soundings. All 2200 PSI of helium in the
tank went into the balloon, which was pulling at the filling adapter
rather strongly by the time we tied it off and attached the payload.
Our balloon wranglers estimated lift at about 10 pounds,
which is over twice the payload mass. When the payload was released,
the Doppler shift of the audio tracking speaker was easy to hear.
The very quick ascent rate made the balloon wander and wobble, which
caused the payload to sway back and forth like a pendulum and caused
us concern as to possible bluring of the pictures (some did, all
air photos are available here).
The flight went flawlessly. Redesigned dust collectors not only
reduced the payload mass, but also cut down the number of metal
components in the gondola. Because of this the tracking signal
didn't suffer the periodic fading that was evident during Flight #2.
The new flight software also performed
as planned. I had deleted the old master mission clock from it (a
leftover from Flight #1), added an 8 second start tone to aid our
trackers, and reduced the inter-picture gap from about 6.5 minutes
to 2 minutes. I also had the program keep track of how many pictures
were left on the film. Not pressing the shutter button when there
were none left kept the only servo quiet and helped conserve battery
life.
The only part of the flight that didn't go flawlessly
was the recovery of the payload:
According to the tracking team, the payload decided to parachute into
a swamp in northern Minnesota. Milly, Blaise, Charlie, and Mark
went above the call of duty and braved swarms of bugs, knee-deep
water, thick vegetation, and poison ivy as they trudged around trying
to locate the payload. It was finally discovered hanging in a tree
(luckily the audio beeper was still working). They recovered it and
brought it back to Grand Forks at about 5:30 PM Central time. The
dust collectors were removed and the film sent to the processing lab
later that day.
More details to follow.
June 11, 1999
Preperations are underway for the third launch of the High Altitude
Balloon Project, planned for tomorrow morning (June 12, 1999).
This flight will be made using the gondola recovered from our
second flight, with a few software
modifications and a longer roll of better-quality film in the onboard
camera.
Blaise, Damien, Milly, and Charlie discuss telemetry sensors.
During the planning meeting for Flight #3, the group decided that the
short time available before the next flight would put a real constraint
on developing new hardware for the flight. A new foam box has been
constructed for the new gondola (above, white with red tape), but
little else. Some of the group
members are still hesitant to fly expensive hardware on a balloon without
a better assurance of its return. Since the group has flown two missions,
with the payload only being recovered from one of them, we felt that
reflying the second payload with only minor modifications would be the
lowest-risk way of further testing our tracking and recovery abilities.
Charlie and John repair minor damage to the payload #2 shelf structure.
For the third flight, the sequencing program for the microcontroller will be modified
to transmit a 5-10 second tone on the radio before telemetry and callsign. This is
per request of some of the hams who helped us track the payload on Flight #2, and
will help them using their directional antennas. The program will also shorten the
interval between 35mm camera pictures. When other group members learned that I
used a roll of cheaper-brand 24 exposure film for the second flight, they gave me plenty
of grief. This mission will use a roll of 36 exposure Kodak 100 ASA film. I also
taped the camera back closed for this mission, so that a rough landing won't
cause the back to spring open and ruin the film.
A new 9 volt lithium battery pack has been constructed for the flight and will be
installed tonight. Along with some better markings and new
dust collectors, these are all the changes being made to the payload.
Launch procedures will be pretty much the same as for Flight #2. I WILL remember to
bring the nylon cable ties this time (luckily Doug had one sitting around that we
used to seal the balloon nozzle last time. Thanks Doug!). This time I will also
feed the upper air winds data into a prediction program to try to guess where the
balloon will go. It was rather embarassing during flight #2 when the chase team,
following some small party balloons we released before the main launch, discovered
they were going the wrong way shortly after the payload was released. Other than
that, everything last time worked quite well.
Return to the UND HABP webpage.